Air cooled internal combustion engine



Oct. 25, 1932. w sMlTH 7 1,884,321

AIR GOOLED INTERNAL COMBUSTION ENGINE Filed Feb. 9. 1929 3 Sheets-Sheet 1 Q Q 1\/ t m N N 4 w .r::: I

' W n E i Q g M j INVENTOR:

WiLLlAM F. SMITH ATTORNEY Oct. 25, 1932. w. F, SMITH AIR COOLED INTERNAL COMBUSTION ENGINE 3 Sheets-Sheet Filed Feb. 9, 1929 WILLIAM F. SMITH,

INVENTOR ATTORNEY ill/ll,

w. 'F. SMITH Oct. 25, f932.

AIR COOLED INTERNAL COMBUSTION ENGINE Filed Feb. 9, 1929 3 Sheets-Sheet wlupmm RSMVFH,

INVENTOR ATTORNEY Patented Oct. 25, 1932 1,884,321

I WILLIAM F. SMITH, OF ,POUGHKEEPSIE, NEW YORK,.ASSIGNOR OF ONEHALF To ,HERMA'N A. SCHATZ, F, POUGHKEEPSIE, NEW YORK AIR OOOLED I NrEnNAL cormUsrmN ENGINE.

Application filed February 9; 1929. fierial- No. 338,767. This invention relates to internal com- F a sectionalview of the engine bustion engines and relates more particularly shown in Fig. 1 taken along lines 4:-4.

to a cooling system. and valve arrangement Fig.5 is-a sectional view of the valve ports for engines of the air cooled type. of the engine taken along lines 55 of Fig. 2.

5 In certain types of air cooled engines now Reference numerals 1 and 2 indicate engine known to the art difficulty is experienced in cylinders which are mounted on the top of a keeping the exhaust valves in good condicrankcase 3. Abutting against theside walls tion. Due to excessive heating these valves of the cylinders l and 2 is an air-duct 14 become warped and burned and in many cases which conducts air introduced into the duct )0 after prolonged use the valve stems also beby a centrifugal type fan 13 mounted in one 00 come warped due to the sweeping of exhaust endof the duct,.aro'und the walls of the engine gases over them in thepassage of the gases cylinders. Inside of air-duct 1i isprovided from the cylinder to the exhaust manifold. a pair of air -deflectors14 and l lbwhich serve hen the valve stem becomes warped'the to divide the air stream delivered by the air 15 valve does not seat and hence is, in a short fan and guide it around the walls of the cylintime, rendered completely useless. de'rs in order "to maintain the correct flow An object of the invention is the provision of air between the cooling fins i8 of the'cyl-- of an air fan and duct for conveying. air inders. Without these deflectors the air around the cylinder and valvegearof an instream, due to its own momentum would tend. 3;) ternal combustion engine to cool the same. to crowd down to the end ofthe duct, and pass Another object is the provision of an araround the cylinder .2, to the detriment of rangement of parts associated with the excylinder 1. After air is blown around the ha-ust valves of an engine cylinder whereby engine cylinders it is carried away by a secsuch valves are kept at uniform tempera- 0nd air-duct 15 which abuts against the, 5:7. ture and are prevented from overheatingand' flanges 66, 67, 64 and 65 similarly toainduct warping. 14. The-fan 13 is illustrated as a single stage A further object is the arrangement of double entry fan but it is to be understood exhaust ports in such manner that exhaust that a single entry fan or a multistage fan gases are prevented from sweeping over the may be used if desired under certain condistems of the exhaust valves. tions. Fan 13 is mounted on a shaft 9 which Still another object is theprovision of an is supported by a bearing 8. positioned in a air-duct and fan for directing a blast of air :sleeve' 7 mounted in an auxiliary housing 5 around the engine cylinders, external valve connected to the crankcase 3, and is driven by gear and spark plugs, for cooling the same. means of a gear 10 secured to shaft 9., which 3.3 These and other objects and advantages gear meshes with an intermediate ring gear 35 and the manner of attaining them will appear 11 which in turn meshes with a pinion 12 more clearly in the following description, mounted on a crankshaft 4 of the engine. taken in conjunction with the accompanying Gear 11, which seryes as an intermediate gear drawings. in the fan driving arrangement, is one of. the to In the drawings, Fig. 1 illustrates in eletransmission gears of the tractor engine and vation and partly in vertical cross section as such serves to drive the bull wheels of the the parts of .an internal combustion engine 'tractor-(notshown) through additional gearnecessary to an understanding of the invening (not shown). Cylinders 1 and 2 are protion. I vided with a pair of flanges 66, 67 and 64, 6'5 Fig. 2 shows a vertical cross section, of a respectively, against which the side walls of cylinder of the engine shown in Fig. 1, taken air-duct '14: are "positioned. The adjacent along lines 22 of Fig. 1. edges of the two pairs of flanges contact and a Fig. 3 is a plan view of one of the cylinders 1 form an air passage between the engine cylinof the engine shown in Fig.- 1 with spark ders. Each cylinder is provided with sir 50 plugs and valve gear removed. cooling fins 48 which surround the; cylinder housings.

for a major portion of its length and is provided at th top with a pair of valve guides 21 and 22 which carry the stems of two valves 19 and 20 respectively. These valves co-o crate with seats 17 and 18 respectively and are provided with the usual valve springs. The valve guides 21 and 22 have cooling fins similarly to the engine cylinders. Cylinders 1 and 2 are provided at the top with housings 1, and 2. respectively. These housings extend over the top of the cylinders and are integral therewith except at the two sides of the cylinders as best shown in Fig. 2,

reference numerals 46 and 47; Mounted upon the sides of housings 1, and 2, are the intake manifold 54 and the exhaust manifold 53, respectively. These manifolds are fixed in place, for example as shown by studs 43 and 44. A pair ofbearings are provided in the top of the housings which serve to hold rocker arm pins 37 which carry rocker arms 23. The rocker arms 23 are actuated by means of push rods 24 which are in turn operated by cams 25 carried on the cam shaft 36, through the agency ofroller 26, guide 28, pin 32 and spring 31, all of which are mounted inside of the valve housing 29 which is enclosed at its top side by a cover In the bottom of valve guide 28 are a plurality of holes 35 which allow for the passage of air and lubricating material to the inside of housing 29. Provided in the housings 1 and 2 are a plurality of exhaust ports 58. These ports 58 communicate with the inside of the engine cylinder through a pair of curved passages, as illustrated in Fig. 5. In this figure represents the chamber back of the valve seat 18 shown in Fig. 2. This chamber 55 communicates through curved passages or ports 60 and 61 with the outlets 62 and 63. The intake ports of the engine may be made either in the same manner as the exhaust ports or may be constructed with one opening in the usual manner. In the sides of the housings 1 and 2 are a plurality of elongated openings 45 which are positioned adjacent to and in line with the spark plugs 59 which are in turn mounted in the head of the cylinders. Enclosing the top of each housing is a cover plate 39 which is held in place by means of cap screws 40. For lubricating the valve mechanisms is provided an oil tube 41 which connects with the crank case at 68 and passes longitudinally through the two housings on top of cylinders 1 and 2. This oil pipe 41 "has a plurality of holes 42 drilled in the sections of the pipe which pass through the two To permit the ready removal of the oil pipe 41 a union 81 is interposed in the pipe line. Oil vapor is breathed up through the pipe 41 by the action of the engine pistons and is forced out through openings 42 in a sort of mist or spray which fills the entire valve housing and precipitates on the worl 1 mg parts and lubricates them. In order to cools them, also a portion of the air s As the crank-shaft 4 revolves fan 13 is driven through the agency of gears 10, 11 and 12 and draws air into the housing 14. This air is forced through the housing 14 and is guided around the walls of the cylinders 1 and 2 at 51 and 50 respectively and between the cylinders at 49. This guiding or distributing of the air stream is accomplished by the air deflectors 14, and 14 which are properly proportioned and positioned to deflect the proper amount of air around the cylinders and between the cylinders. Af er being forced around the walls of the CYilllClCl'S the air is guided away through the air-duct 15. A portion of the air delivered by fan 13 through airduct 14 is diverted and passed over the top of the cylinders and around the valve stems and spark plugs. This portion of the air passes into the housings 1 and 2., through openings 46 and out of the housings through openings 45 and 47. The comes into the housings through openings 46 passes over the valve stems and guides and is diverted through openings 45 and is projected against the spark plugs to cool them.

The remaining portion of the air passes at of the housings through openings 47. This passage of the air over the head of the cylinder serves to cool the valve stems and carry heat away from the valve seats in very efiicient manner. It will be noted that the valve stems are made very short and that the material forming the head of the engine is made of substantially a uniform thickness throughout, due to the particular censtruotion permissible with the type of cooling arrangement which I have shown. The fact that the valve stems are short permits of greater cooling of the valve seats. The pas sage of the air around the valve stems, cylinders and spark plugs has been indicated on Figs. 1, 2, 3 and 4 by arrows. The fan 13 is preferably so designed as to force air through the duct at a considerable pressure in order to create turbulence of the air stream and insure efiicient contact between the cooling air and the engine cylinder walls and ir which 5 By this arrangement exhaust gases passing from the engine cylinder are divided and caused to flow equally through the two passages, whereby exhaust gases are prevented from washing over the valve stems in their passage from the engine cylinder to the ex til body.

haust manifold. This feature is best shown in Fig. 5 where it will be noted that any gases tending to leave the engine cylinder will pass to chamber 56 back of seat face 55, d1- vide and pass equally through passages 60 and 61 and out of ports62 and 63 to the exhaust manifold. By this arrangement it is possible to prevent warping of the valves due to unequal heating of the valve stems and also to keep the valves at a much lower temperature due to the facts both that the valve stems can be made short and that the valve stems are not heated to sohigh a temperature by the washing of the hot engine gases over them, p

The cooling arrangement which I have disclosed is particularly eflicient due to the fact that the air blast is passed first over the exhaust valve stem and around the exhaust valve ports before passing over the other porions of the cylinder head. This produces greater cooling of the ports becausethe cold air is projected against the hottest portion of the cylinder head first. This prevents undue heating of the exhaust valve, which is the valve which ordinarily gives the greatest amount of trouble in an air cooled engine. Another feature which greatly aids in the cooling of the valve gear and cylinder head is the fact that the material of the head and of the valve ports is made relatively thin and of substantially an even thickness throughout. This results in an even transfer ofheat from the cylinder head at a maximum rate. Due to the particular. construction of the cylinder head it will be noted that air is caused to circulate substantially around the entire plugs also cause air to be circulated downwardly between the two valve seats in such manner as to cool the surface between the valve seats effectively; Due to the particular construction set forth, the seat of the exhaust valve is constantly surrounded by a moving streamof cool air which tends to remove heat from the valve'seat and valve stem at a high rate and to keep the valve structure uniformly cool throughout its entire Valves 19 and 20 are operated through the agency of the rocker arm 23 which is in turn actuated by the push. rod 24. Push .rod 24 is secured by a pin 32 tothe guide 28 which is'slidably mounted in housing 29, secured by flange to the crankcase of the engine. As cam 25 is rotated by the cam shaft 33 in a right-handed direction from the position as shown in Fig. 20f the drawings, roller 26 will be thrust upward carrying with it guide 28, to which it is connected by means of a yoke 27. As the guide 28 travels upward it will push upward the rod 24 and the righthand end of the rocker arm 23, thus allowing valve 19 to close. Both valveswill remain 23 in a counterclockwise direction and opening the valve 20. After the valve 20 has been opened to its fullest extent the roller 26 will move on to the downward pitch of the cam 25 and shut the valve 20. Then, as the cam rotates still further the roller 26 will descend into the hollow of the cam 25 in the position as shown in Fig. 2 of the drawings and in dropping into the said hollow will allow the guide 28'to be pushed into a downward position by the compression of spring 31. This downward movement of the guide 28 serves to open the valve 19 due to the fact that the compression of the spring 31 is much greater than that of the spring of valve 19. The push rod 24.- attached to the guide 28 at a point substantially midway between the ends of the guide; This arrangement of parts distributes the side thrust of the push rod evenly between the top and bottom of the guide 28 and the housing 29, thus reducing wearing of the parts to a large extent. The holes 35 allow oil vapor to pass into the inside of the housing 29 and lubricate the guideand pin 32. These holes 35 also serve to prevent compression of air-within the housing 29. It will be seen that the valve gear arrangement as shown eliminates the necessity of two push rods for each cylinder and permits, in a simple and eflicientmanner, one push rod to operate two valves.

It will be obvious to those skilled in the art that the invention is capable of a wide variety of modifications and adaptations and that the present disclosure is intended merely to illustrate its nature without limiting its scope which i defined in the claims.

. What I claim is: a I

1. An engine cylinder comprising a wall and a head, said wall having cooling fins integral therewith, said head havingpositioned thereon a housing, an air passage in said housing opening downwardly towards said wall, a sparkplug mounted in said head outside of said. housing a hole in said housing opposite said spark plug, and means for blowing air through said passage into said housing. I

2. An internal combustion engine of the air cooled type comprising a pair of engine cylinders mounted side by side, an air-duet, flanges integral with the top and bottom of each of said cylinders, and extending at right angles to the axis of the cylinders, said flanges cooperat ng with each. other and the air duct to form air passages around and between said cylinders, a housing on top of each of said cylinders and openings in said flanges interconnecting sald housings with sald airduct.

An engine cylinder comprising a wall and a head, said wall having cooling fins integral therewith and an air-duct positioned at right angles thereto, said head having a housing integral therewith, an air passage interconnecting said housing and said airduct, a spark plug mounted in said head outside of saidhousing,an air passage through said housing opposite said spark plug, and means for forcing air into said air-duct.

4:. An engine cylinder comprising a wall and a head, a housing mounted on said head, a valve seat in said head within said housing, a pair of spaced valve ports communicating with said valve seat and extending out through the side of said housing and an air passage extending through said housing between said valve ports.

5. An internal combustion engine cylinder comprising a valve seat, a valve stem guide, a pair of valve ports extending from said valve seat in opposite directions away from said valve stem guide, and means for blowing a blast of air over said cylinder between the walls of said valve ports.

6. In an internal combustion engine a cylinder, a valve seat, a pair of similarly upwardly curved valve ports extending away from said valve seat in opposite directions, and means for directing a blast of air transversely between the walls of said ports.

7. An internal combustion engine cylinder comprising an exhaust valve seat, a chamber adjacent to said seat, a pair of exhaust ports extending away from said chamher in opposite directions, a valve guide ex tending from said chamber, and means for subjecting said guide to a transverse blast of cooling air.

8. An engine in accordance with claim 7 wherein the exhaust ports curve upwardly and said valve guide is positioned in the channel between the walls of said ports.

9. An internal combustion engine comprising an exhaust valve having a stem, means for conducting exhaust gases away from said valve in opposite directions, and means for cooling said stem.

. 10. An internal combustion engine comprising a cylinder, inlet and exhaust valve chambers in the head of said cylinder, a pair of ports connecting at opposite sides with each chamber and extending upwardly and outwardly away from said cylinder head, and means interconnecting the inner sides of the walls of corresponding ports of the two chambers to form a' channel for conducting cooling air.

11. An engine in accordance with claim 10 wherein means is provided for passing a blast of air through said channel from the exhaust valve side toward the inlet valve side.

12. An engine in accordance with claim 10 wherein the material of the cylinder head forming the valve chambers is of uniform thickness and wherein there is an opening in the'side of said channel at a point between said chambers.

13. An engine in accordance with claim 10 wherein the material of the cylinder head forming the valve chamber is of uniform thickness, a spark plug is positioned in said head and an opening is provided in the side of said channel at a point opposite said spark plug so that air forced through said channel will pass out of said opening and strike, said plug.

14. An internal combustion engine comprising a cylinder head, an inlet and an exhaust valve in said head, members extending across said head on each side of said valves to form an air channel, and means for passing a blast of airthrough said channel from the exhaust valve end to the inlet valve end.

15. In an internal combustion engine, a block providing a surface for cooling fluid and having an opening which provides a. seat for an exhaust valve; and a plurality of divergent exhaust passages leading from said opening through space cooled by fluid to separate outlet ports from said block.

16. In an internal combustion engine, a block providing a surface for cooling fluid and having an opening which provides a seat for an exhaust valve having a stem; and a plurality of exhaust passages leading from said opening through space cooled by said fluid to separate outlet ports from said block, walls of said passages being divergent from said seat opening and spaced from said stem.

17 In an internal combustion engine, a block providing a surface for cooling fluid and having an opening which provides a seat for an exhaust valve having astem; a valve stem guide extending through space cooled by said fluid; and a plurality of exhaust passages leading from said opening through said space, inner walls of said passages being divergent from said seat opening and so spaced from said guide as to admit cooling fluid to substantially the entire length thereof.

18. In an internal combustion engine, a block providing a surface for cooling fluid and having an opening which provides a seat for an exhaust valve having a stem; and a plurality of exhaust passages leading from said opening through space cooled by said fluid to separate outlet ports from said block, inner walls of said passages being spaced from one another and a guide for said stem being disposed therebetween and out of contact therewith.

19. In an internal combustion engine, a block providing a surface for cooling fluid and having an opening which provides a seat for an exhaust valve having a stem; and a plurality of exhaust passagesleading from said opening through space cooled by said ported from said bridge.

fluid to separate outlet ports fromsaid block, said stem being provided with a guide extending through said space and so spaced from said passages as to expose said guide substantially throughout the length thereof to cooling fluid in said space.

20. In an internal combustion engine, a block providing a surface for cooling fluid and having an opening which provides a seat for an exhaust valve having a stem; and a plurality of exhaust passages leading from said opening through space cooled by said fluid to separate outlet ports from said block, said stem being provided with a guide extending through said space. and having the form of an exposed cylinder throughout substantially the entire length thereof.

21. In an internal combustion engine, a block providing a surface for cooling fluid and having an opening which provides a seat for an exhaust valve having a stem; and a plurality of oppositely curved exhaust passages leading from said opening through space cooled by said fluid space, said stem being provided With a guide so extending through said space between said passages as to expose both said guide and said passages to the cooling fluid throughout substantially the entire length thereof.

22. In an internal combustion engine, a block providing both a valved exhaust opening and a fluid cooled surface enclosing a space through which extends a valve stem guide; and a pair of exhaust passages divergent from said opening and spaced from said guide.

23. In an internal combustion engine, a block providing both a valved exhaust opening and a fluid cooled surface enclosing a space through which extends a valve stem guide; and a pair of exhaust passages divergent from said opening and leading to separate ports in said block.

24. In an internal combustion engine, a block providing both a valved exhaust opening and a fluid cooled surfaceenclosing a space through which extends a valve stem guide; a pair of exhaust passages divergent from said opening and leading to separate ports in said block; and a manifold, in engagement With said block, provided with correspondingly spaced openings.

25. In an internal combustion engine, a block providing both a valved exhaust opening and also a fluid cooled surface enclosing a chamber through which extends a valve stem guide; a bridge extending transversely of said opening and supporting one end of said guide; and a pair of exhaust passages divergent from said openingand also sup- In testimony whereof, I have signed my name to this specification this 7th day of February, 1929.

WILLIAM F. SMITH. 

